This invention relates to audio power management.
Personal computers, and especially portable personal computers frequently use power management methods to reduce power consumption either in periods of disuse or when power resources are changed, for example, when power is switched from AC line current to a battery. Power management methods typically include shutting down or "graying out" a computer display, shutting down most of the central microprocessor activity, reducing memory power consumption, and turning off spinning disk drives.
Audio systems in personal computers have grown sophisticated, with sound synthesis generators, filtering, automatic gain control, stereo channels, and other high quality features. As audio systems become more sophisticated, their power demands increase. High quality audio power systems may require in excess of 4 watts of power under peak conditions. Such power demands may be especially difficult to sustain in portable computers, where conservation of battery resources to maximize user time between chargings is often a priority.